added start_date and end_date

modified test country

Added admin_level to Czech

Adding Yugoslavia -part 3

Adding Yugoslavia -part 2

Adding Yugoslavia -part 1

Adding Greece -Part 8

Adding Greece -Part 7

Adding Greece -Part 6

Adding Greece -Part 5

Adding Greece -Part 4

Adding Greece -Part 3

Adding Greece -Part 2

Adding Greece -Part 1

Added parts of Greece Turkey border

Adding Bulgaria -Part 6

Adding Bulgaria -Part 5

Adding Bulgaria -Part 4

Adding Bulgaria -Part 3

Adding Bulgaria -Part 2